Field of the Invention
The present invention relates to a process for modifying a film of a semiconductor substrate and, more particularly, to a technique for inspecting a modification state.
Description of the Background Art
During a manufacture of a semiconductor device, a film quality process for modifying the quality of a film of a semiconductor substrate by irradiating a surface of the semiconductor substrate with light has been performed (for example, as disclosed in Japanese Patent Application Laid-Open No. 2011-014914, Japanese Patent Application Laid-Open No. 2008-004694 and Japanese Patent Application Laid-Open No. 2014-078660).
Japanese Patent Application Laid-Open No. 2011-014914 discloses the technique of irradiating a silicon substrate with a pulsed laser having a pulse width of 10 to 1000 femtoseconds to activate impurities.
Japanese Patent Application Laid-Open No. 2008-004694 discloses the technique of modifying a surface of a GaN substrate by the use of an ultrashort pulsed laser such as a femtosecond laser. More specifically, Japanese Patent Application Laid-Open No. 2008-004694 discloses the technique of irradiating the surface of the GaN substrate with the pulsed laser to form an irregular structure, to form an amorphous region or a strain region and to relax a strain.
Japanese Patent Application Laid-Open No. 2014-078660 discloses the technique of heating a region implanted with impurity ions in a wide-gap semiconductor by laser annealing to activate the impurity ions.
Unfortunately, it has been necessary for the conventional techniques to repeatedly perform a modification process and the inspection of a modification state in alternate order to set conditions for light irradiation for the purpose of performing the modification process under preferable conditions. Thus, complicated operations and time-consuming feedback have been required for the optimization of the conditions for light irradiation.